Clearwire Corp agreed to sell a roughly 50 percent stake for $2.2 billion to majority shareholder Sprint Nextel Corp, which would then have full ownership of spectrum that will help it offer high-speed wireless services.

The $2.97-per-share deal is only 7 cents per share higher than a bid many minority shareholders said was too low days before. Clearwire (Bellevue, USA) shares slid 9.8 percent to $3.04 in premarket trading.

But it was not immediately clear whether Sprint, the No. 3 U.S. wireless carrier, could win the backing of a majority of Clearwire's minority shareholders, which it needs to take control.

Shareholders with more than 13 percent of Clearwire shares had told Reuters last week that they were not happy with the $2.90-per-share offer, and some shareholders have said Sprint should offer as much as $5 per share.

Clearwire, which also counts Sprint as its biggest customer, has been seeking financing for a high-speed wireless network upgrade and to keep itself afloat.

While some analysts and shareholders said Clearwire did not need to rush into a sale to Sprint, others have said that move would be its best hope for survival.